The present disclosure relates, in general, to electronics, and more particularly, to circuits and method for powering Light Emitting Diodes (LEDs) from Alternating Current (AC) power supplies. In the past, such circuits used power conversion circuits, such as Switched Mode Power Supplies (SMPS), to convert the AC power before supplying it to the LEDs.
Alternatively, Direct Alternating Current Drive (DACD) LED systems provide the AC power to the LEDs without conversion. DACD LED systems can be simpler, smaller, and have fewer components than SMPS systems, while still achieving high efficiencies, good power factors, and low Total Harmonic Distortion (THD). In addition, DACD LED systems may be compatible with a variety of dimming techniques, such as phase-cut dimming, analog dimming, and Pulse Width Modulation (PWM) dimming.
Accordingly, it is desirable to develop cost-effective DACD LED systems.
Those skilled in the field of the present disclosure will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of the embodiments.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments. This avoids obscuring the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the disclosures herein. The details of well-known elements, structures, or processes that are necessary to practice the embodiments and that are well known to those of skill in the art may not be shown and should be assumed present unless otherwise indicated.